1. Field of the Invention
The present invention relates to a mechanical actuating device for opening or closing a valve that controlling a nozzle movable along a present trajectory with respect to a support.
2. Discussion of Background Information
More especially, this actuating device finds application on carriage construction machinery, such as finishers, for instance of the same type as those described in commonly assigned application for French patent FR-90.06306 dated May 21, 1990, entitled "Spreading device for a fluid material or analogical, especially a bonding emulsion for bituminous coated materials, over a road surface and carriage way construction machinery, especially finishers, comprising such a device", which was published as FR-A-2,662,193 on Oct. 30, 1992, and is a family member of U.S. patent application Ser. No. 07/685,952, filed Apr. 17, 1991. The finishers described in this application are fitted with a spreading assembly enabling the spreading of bonding emulsion for bituminous coated materials, together with applying the coated materials over the road surface. This spreading assembly comprises mainly, on a mobile finishing vehicle, at least one spreading rail fitted with nozzles, and in order to perform the spreading operation of the whole width of the road, a mechanism for moving the spreading rail from one side to the other, transversely with respect to the displacement direction of the mobile finishing vehicle.
It has appeared necessary, especially for adjusting the spreading width, to add a device to control the opening or the closing of the nozzles when they pass through a given point on their transverse path with respect to the chassis of the mobile finishing vehicle. This point may be a limit of the spreading width, for instance.
A classic remedy for this problem would have consisted of using servovalves. But the spreading assembly would have been far more expensive and far more complex.
By the present invention there is provided an actuating device, for opening or closing a valve controlling a nozzle, which is exclusively mechanical.